JPH0688255B2 - Release method - Google Patents

Abstract

A process which comprises (i) the generation of release surfaces by application to predetermined areas of a solid surface of a solution, suspension or dispersion of a release agent and a supercritical fluid that vaporizes from the release agent, (ii) the deposition of a mass onto the release surface containing the release agent, and (iii) the separation of the mass or a product derived from the mass from such surface covered by the release agent. Novel apparatus for carrying out the process are described.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a) a solution, suspension or a solution of a release agent on a predetermined portion of a solid surface and a supercritical fluid evaporated from the release agent. Creating a non-stick surface by applying the dispersion, b) depositing a mass of material on the non-stick surface containing the release agent, and c) coated with the release agent. It relates to a method comprising separating from the surface such a mass of material or a product derived from this mass of material. The invention also relates to a new device for implementing this method.

[Conventional technology]

The use of supercritical fluids as a transport medium for the formation of surface coatings is known. German Patent Application No. 2853066 describes the use of supercritical gas as a fluid medium for dissolving solid or liquid coating materials. In particular, this application is a protective agent by realizing the coating of a porous body by a combination of immersion of the porous body in a supercritical fluid and pressure drop, or a decorative finishing paint which is reactive or non-reactive. The method for coating with is intended. The most important porous body is the porous catalyst. However, this application features a woven fabric as a porous body.

United States Patent No. 4,58, granted to Smith on April 15, 1986
No. 2,731 and U.S. Pat. No. 4,7 granted March 29, 1988
34,451 describes making a supercritical solution containing a supercritical fluid solvent and a solute of a dissolved solid material, and spraying this solution to form a "molecular spray". "Molecular spray" is defined here as a spray of "individual molecules (atoms) or very fine particles of a solute". The Smith patent covers the production of thin films and fine powders. These thin films are used as surface coatings.

Some related applications of the present invention generally relate to forming coatings using supercritical fluids to reduce the viscosity of the coating composition. These related applications use carbon dioxide (CO ₂ ) to create a supercritical fluid.

Hoy et al.'S US patent application No. 1 filed December 21, 1987
33,068 describes a method and apparatus for liquid spray coating a coating material onto a substrate, which minimizes the use of organic diluents which are environmentally undesirable. The method of this application is: 1) a) in a closed system, a) at least one polymer compound capable of forming a coating on a substrate, and b) when added to b) above. A) and a liquid mixture comprising at least one supercritical fluid in an amount sufficient to make the viscosity of the mixture with a suitable size for spray painting, and 2) spraying the liquid mixture onto a substrate. Then, each step of forming a liquid coating film on this is included.

The above application also includes at least one or more active organic solvents c)
It also relates to a liquid spray coating method in which the final mixture is mixed with the above-mentioned a) and b) prior to the liquid spray coating on the substrate. A preferred supercritical fluid is supercritical carbon dioxide. The method uses a device that allows the components of the liquid spray mixture to be mixed and sprayed onto a suitable substrate. This apparatus is 1) means for supplying at least one or more polymer compounds capable of forming a continuous coating film in close contact, 2) means for supplying at least one or more active organic solvent, 3) supercritical carbon dioxide fluid 4) means for forming a liquid mixture of the respective components supplied from 1) to 3) above, and 5) means for spraying the liquid mixture onto a substrate.

The device may also comprise means 6) for heating any of the above components and / or a liquid mixture of the above components. U.S. Patent Application No. To be used as a diluent for coating to the coating viscosities required for liquid spray technology. The above application also shows that the method is generally applicable to all organic solvent based coating systems.

Co-filed US Patent Application No. 21 filed July 14, 1988
No. 8,910 is a method of applying a liquid coating composition such that various supercritical fluids such as supercritical carbon dioxide fluids are used to reduce the coating viscosity so that various viscous coating compositions can be applied as liquid sprays. And its device.

The method of the above-referenced US Patent Application No. 218,910 for applying various coatings on a substrate by a liquid spray coating method is particularly: 1) in a closed system a) forming a coating on the substrate At least one polymer compound which is capable of being mixed with (b) the mixture of (a) and (b) when added to the above (a), in an amount sufficient to make the viscosity of the mixture suitable for spray coating. Forming a liquid mixture consisting of a solvent component including a supercritical fluid, and 2) flowing the above liquid mixture under pressure through the outlet holes around the substrate to form a liquid spray on the substrate. Each step of spraying the liquid mixture to form a liquid coating film on the liquid mixture is included.

U.S. Patent Application No. 218,895, filed July 14, 1988, uses 1) a supercritical fluid, such as a supercritical carbon dioxide fluid, as a viscosity reducing diluent in a coating composition, and 2) Forming a liquid spray by flowing a mixture with the coating composition under pressure through the exit holes and around the substrate, and 3) electrically charging the liquid spray at a higher voltage than the substrate. And a method for coating the above substrate by liquid spray. In particular, the method of U.S. Pat. No. 218,805, in which various coating materials are electrostatically liquid spray coated onto this substrate, comprises: 1) in a closed system a) forming the coating on the substrate. At least one polymer compound which is capable of being mixed with (b) the mixture of (a) and (b) when added to the above (a), in an amount sufficient to make the viscosity of the mixture suitable for spray coating. Forming a liquid mixture consisting of a solvent component containing a supercritical fluid, and 2) flowing the liquid mixture under pressure through the outlet holes to the periphery of the substrate to form a liquid spray on the substrate. Spraying the liquid mixture to form a liquid coating on it, and 3) electrically charging the liquid spray with a higher voltage and current than the substrate.

Various solid non-stick surfaces are used in many applications in industry. The function of the non-stick solid surface is to allow a substance to be deposited on the surface and remove it from the surface without sticking the substance to the surface. One method of forming a non-adhesive solid surface is to deposit a release agent on the surface and to ensure that any material placed on the surface is not adversely affected by such a release agent. That is, the mold release agent is used to mold the surface. Applying various mold release agents on solid surfaces raises a number of problems, some of which are still poorly addressed. For example,
When the non-stick surface is a hot surface, the presence of the release agent on this surface creates a temperature gradient towards the mass of material placed on it. If the release agent is applied unevenly, an uneven temperature portion will appear across the surface of the applied release agent. This means that the substances applied on the surface containing the release agent are subject to different thermal effects. There is almost no case where such a difference in thermal action does not affect the property of the object.

One problem associated with the delivery of release agent onto the surface to be imprinted is the non-uniform deposition due to the large amount of release agent that must be used. For example, the normal spraying of a release agent onto a release surface is such that the release agent solution (generally dissolved in a solvent) by gas under pressure.
Including ejecting. The spray consists of mold release agent droplets which aggregate on the sprayed surface to form a coating of considerable thickness. If the mold release surface is a mold, a mold release agent is sprayed into the mold and deposited on the mold surface. The material to be cast is fed into the mold and the surface of the mold is shaped under heat and pressure. Under its actual operating conditions, the release agent acts as a barrier that keeps the casting material from contacting the mold surface. Release agents accomplish this in three ways: in the form of gas, liquid or solid. It volatilizes to create a vapor barrier to its surface, or starts from the solid state and liquefies without vaporizing to form a liquid barrier, or it starts from the liquid state and vaporizes without vaporizing. To form a liquid barrier, or
It is sprayed onto the mold from a solvent-containing solution, and the solvent evaporates in the mold to deposit a solid waxy film. In almost all cases, a reduction in the viscosity of the release agent occurs which allows the formation of a more uniform coating across the mold surface.
However, this means that the release agent is a gas on the mold surface,
It is not meant to be present as a uniform layer of liquid or solid. If the amount of release agent is excessive in any part of the mold, the mold surface will eventually be coated unevenly. The heat drawn from the mold surface by the material supplied to and processed in the mold is not evenly imparted to it, and this thermal deviation can adversely affect the casting produced. Such adverse effects typically appear on the surface of the casting.

In the case of unevenly shaped or hollow molds, the sprayed mold release agent tends to collect to form a thicker layer due to the flow towards the lower surface portion in the mold due to gravity. As a result, there will be a significant temperature non-uniformity appearing in the cast material across the mold surface. This does not mean that there is no templating agent in such parts of the template surface, but points out that there is an excess of release agent in such parts of the template surface. Should be.

Even if the release agent is a layer applied uniformly on the release surface, this layer is relatively thick enough to penetrate into the mass of material fed in contact with that surface.

For example, when baking various things in a frying pan, a mold releasing agent made of vegetable oil is used on the surface of the frying pan. Such oils penetrate into the mixture of the ingredients to be baked so that the surface of the baked material is essentially "French fried" by the vegetable oil, and the surface of the baked material is It exhibits different properties. In fact, if the conditions change, it is enough to see if the material is properly fired.

Some plastic materials contain various components, crystalline and amorphous. Release agents that penetrate the interior can erode both layers to the extent that the surface of the molding differs from the interior. Many molded plastic products are used in applications such as food contact. A significant problem is the presence of mold release agents adhering to the surface of the resulting molded plastic part, which impairs the usefulness of the molded article in some uses of the plastic article. For example, even a very thin layer of release agent on the surface of such a plastic product needs to be removed from the product, which would otherwise result in a loss of taste and mouthfeel in the food product in contact with the product. Let's do it.

Even when the normally sprayed release agent is a uniformly coated layer on the release surface, this layer is relatively thick, so this thick layer is a surface for subsequent coating of that surface. Hinder the use of mold release agents in various masking areas.

There are many different industrial applications in which the coating is limited to only certain locations on the surface so that the unpainted surface can later be used in other ways. For example, various parts of the metal surface may be painted first, and the other parts may be left unpainted so that they can be used for carrying out the face-to-face bond. An example of this is automobile or aircraft parts that are adhesively joined to other parts. In the case of solid electronic circuits, various parts of the surface of the dielectric material are first masked prior to printing the electronic circuit. One problem that exists in such a technical field is that in industrial mass production conditions, painting or masking is performed, and the ratio of unpainted portions for painting after the surface occupies the minimum portion of the entire surface. That is, it cannot be applied in the form. The coating material has a tendency to flow and move, and thus a larger area than is required to be the functional surface in the next coating to ensure that the unpainted surface remains unpainted. The unpainted surface must be left behind. This becomes a greater problem if the surface is to be dip coated. When using the dipping method, it is extremely difficult to leave the unpainted surface. Otherwise form some unpainted parts on the surface to be dip coated and the release agent applied on this unpainted part does not adversely affect the surface part to be dip coated It is desirable to do so.

Surfaces to be painted with a paint release agent are pretreated on the surface parts which must eventually remain unpainted, and then a final coating or masking is applied to the surface containing the above paint release agent. It is desirable to be able to apply to all surfaces, including parts, and complete their processing steps to cure or dry this coating or masking. After such a treatment is completed, the surface part covered with the coating release agent is brushed to remove the unbonded part of the coating coating or the mask to remove the surface containing the coating release agent. You can leave.

The feature of such a masking method is that the size of the unpainted portion of the surface can be minimized. This minimizes the amount of unpainted and unbonded areas on the surface.

This technique is only effective when the release agent does not move during or prior to the painting operation and can be easily removed from the substrate. Transfer of release agent will occur during some stage of the coating process, often due to the excess release agent that will be applied to the surface by various conventional methods. This increases the unpainted part of the surface in an uncontrollable manner.

The method also requires that the release agent on the unpainted portion of the surface be easily removed from the surface so that the unpainted surface is not prevented from further use.

[Problems to be Solved by the Invention]

Many release agents are highly viscous and have high boiling or high melting points under normal ambient temperature and pressure conditions, so in order to apply them to a release surface, the viscosity is applied to this surface. That means when you need to lower it. This means that the release agent must be diluted with solvent. Even assuming that the solvents are toxicologically safe, their use poses environmental problems.
It is believed that when they volatilize, they are released into the atmosphere and promote smog formation. For example, hydrocarbon solvents have hitherto been widely used as solvents for release agents. There is good reason for these solvents to create environmental problems in order to promote smog formation, and therefore aqueous-based release agent compositions have been developed to prevent the release of such organic solvents. However, the performance of these aqueous-based compositions is very unsatisfactory compared to that of hydrocarbon-based ones: they have not been successful in providing good release properties, they are This results in wastewater problems, and because they have a negative impact on the temperature of the surface being treated.

[Means for Solving the Problems]

A new system has been found for applying and then removing a release agent to those surface areas where other materials come into contact with it. This system allows the release agent to be applied uniformly to the release surface, and provides one or more of the following advantages: o The use of organic solvents can be eliminated or minimized. be able to.

The concentration of the release agent on the release surface can be substantially reduced.

○ A solid release agent can be used in a part where a liquid release agent has been used so far, because this release agent should be uniformly deposited as fine particles on the release surface. Because you can

○ This mold release agent can be applied as a liquid from a position very close to the spray head of the spray device leaving a slight gap, and the spray exists as a mist of fine particles, and all of the particles are It has a much higher viscosity than that of its original liquid.

○ This release agent should be applied to a smaller surface area than that covered with other materials so that other materials may cover the surface area containing this release agent and the surface area without the release agent. Can be applied.

O The release agent can be applied using standard spraying techniques.

The present invention is i) spray coated over a predetermined area of a solid surface with a mold release agent obtained from a solution, suspension or dispersion of a mold release agent and a supercritical fluid which is volatilized from the mold release agent. Creating a non-stick surface by ii) depositing a mass of material on the non-stick surface containing the release agent, and ii)
i) a method comprising separating this mass of material or an article derived from this mass of material from such a surface coated with a release agent.

More particularly, the invention relates to i) a mold release agent obtained from a solution, suspension or dispersion of a mold release agent and a supercritical fluid evaporating from the mold release agent through the exit hole from the high pressure zone to the exit hole. By spraying so as to form a spray of release agent particles that is blown into a low pressure zone outside of the solids and deposited on a predetermined portion on a solid surface, preferably that portion. To produce a non-stick surface as an essentially uniform coating covering ii) a mass of material is deposited on the non-stick surface containing the release agent, and iii) this mass of mass or a product derived therefrom. From the surface coated with the release agent.

The present invention has broad industrial applications and encompasses technical fields such as plastic products, molding of various synthetic resins and elastomers, baking of foods and coating of various surfaces, all of which are plastics. It utilizes non-stick surfaces that prevent materials, resinous materials, food products and coatings from adhering to the substrates on which they are supplied or applied. Broadly speaking, the present invention provides that although the curable substance is deposited on a surface where it is not desired to adhere to it, the nature of this and that of its surface make it hard to cure on this surface. The present invention can be used in all cases where it is difficult to cleanly remove all of the deposits from the surface and adheres to the surface to some extent. The present invention provides a method of preventing such adhesion.

The present invention provides a method for uniformly depositing a thin layer of release agent on a predetermined surface in such a manner as to minimize, if not eliminate, any migration of release agent from this portion. Include. The present invention also provides a predetermined surface with a thin layer of release agent that sufficiently minimizes and preferably essentially eliminates penetration of the release agent into the subsequently applied material. It also includes a method of depositing on. Thereby it is possible to obtain moldings or baked products in a manner without surface hardening brought about by the interaction between the release agent and the moldings or baked products, whereby the products or molded products are made into their entire internal structure. Becomes more uniform across. in addition,
According to the method of the present invention, the mold release agent is almost and still present in the surface portion in contact with it, even if it is coated with a solvent-containing liquid such as lacquer, ink or the like. A very limited amount of release agent is provided on the surface of the substrate, even though it flows very little.

Due to the very small amount of release agent provided on such a surface, this release agent can be readily adapted for subsequent deposition on its non-adhesive surface and its treatment.
In fact, the amount of release agent is not detrimental to the subsequent treatment of the non-adhesive surface for other purposes, so that the release agent can be used before this surface is used for such other purposes. There are often times when it is not necessary to remove residual amounts from the non-stick surface to clean. In any event, however, the present invention provides a release agent in such a small amount that it requires little effort to prepare it for subsequent processing in order to provide the desired non-stick property to the surface. Only use it on its non-stick surface. As such, the present invention is particularly desirable for use with various coating purposes when it is desired to provide a non-stick surface on the object to be coated. The target surface can thus be optionally coated even by the dipping method, and the relatively thick coating produced by the dipping method is easily removed from the non-stick surface by brushing the surface. be able to. Therefore, it is not necessary to provide a masking material or intercalating material on the surface to prevent the selected surface on the object from being covered, and thus avoiding complex process steps. .

The preferred use of the present invention is in the field of producing a molded article by casting a thermosetting resin and a thermoplastic resin, in which case the thermosetting resin and the thermoplastic resin are separated from each other on the inner surface of the casting mold. Spray a mold release agent obtained from a solution, suspension or dispersion of a mold agent and a supercritical fluid that evaporates from this mold release agent, and contact the thermosetting resin or thermoplastic resin with the inner surface of the mold. Feeding and molding therein, thereby forming a molded article of the same shape as the mold, and the resulting molded article is essentially, if not completely free of mold release agent. Remove from mold in a manner.

Examples of such thermosetting resins are crosslinkable acrylic resins, phenol-formaldehyde resins, alkyd resins, melamine-formaldehyde resins, unsaturated polyesters, epoxides and the like. Examples of thermoplastics include polyethylene, polypropylene, polystyrene, polyacrylates, PVC, polycarbonates, polysulfones, ionomers and reinforced plastics.

The present invention also includes methods and apparatus for applying a release agent composition to a mold surface that minimizes or eliminates the use of organic solvents. The method is 1) capable of forming a thin coating layer on the mold surface i) in a closed system at least 1.
One or more mold release agents, ii) at least one supercritical fluid, and iii) optionally dissolving and suspending a reduced amount of such mold release agent, including minor amounts, such as secondary amounts. Or 2) forming a liquid mixture comprising an active solvent that can be dispersed, 2) spraying the above liquid mixture onto the surface of the mold to form a thin film of the releasing agent thereon, 3) the above releasing agent The step of introducing a molding composition into the surface of the mold on which the thin film containing the above is placed to mold the composition, and 4) removing the molded composition from the mold.

The present invention is applicable to many molding methods, such as reaction injection molding (RIM), injection molding, compression molding, bulk molding, transfer molding, cast molding, spin cast molding, casting, vacuum molding, and blow, when applied to mold molding. It has particular utility in molding, calender molding, laminated molding, foam molding, rotational molding and the like.

The present invention need not, in most cases, be a material for which release agents are uncommon for that purpose. Standard mold release agents may be used in the process of the present invention, and such standard mold release agents may be used in the practice of the present invention by virtue of diluting the mold release agent with a supercritical fluid. Will be possible. Thus, the release agent can be a liquid or waxy substance having the release characteristics required for the substance to which it is applied. In one of the preferred embodiments of the present invention the method comprises: 1) in a closed system i) at least one capable of forming a thin coating layer on the mold surface
One or more waxy compounds, ii) at least one supercritical fluid, and iii) optionally dissolving and suspending a reduced amount, such as a minor amount, including minor amounts, of the above waxy compounds. Or 2) forming a liquid mixture consisting of an active solvent that can be dispersed, 2) spraying the liquid mixture onto the mold surface to form a thin wax layer thereon, 3) adding the release agent Introducing the molding composition into the mold surface containing the thin wax layer to mold the composition, and 4) removing the molded composition from the mold.

The present invention has particular application in the molding of polyurethanes such as polyurethane resins and polyurethane foams including, for example, forming polyurethane in situ or forming polyurethane foam in an open or closed mold. is there. The difference between the molding of polyurethanes or polyurethane foams according to the invention and that of the prior art is that in the present invention a mold release agent and a supercritical fluid evaporating from this mold release agent on a predetermined part of the surface of a solid mold. The mold is pretreated by spray coating a release agent obtained from the solution, suspension or dispersion of

The present invention includes a method for preparing a mold and an apparatus therefor in which a compound containing an active hydrogen group and an isocyanate compound are polymerized to form a molded article obtained by molding the casting mold therein. This mold is capable of forming 1) in a closed system i) a thin coating layer on the mold surface prior to the polymerization.
One or more waxy compounds, ii) at least one supercritical fluid, and iii) optionally a low amount of an active solvent in which the waxy compounds can be dissolved, suspended or dispersed. 2) spraying the liquid mixture onto the mold surface to form a wax layer thereon, 3) contacting the sprayed mold surface with an active hydrogen group-containing compound and an isocyanate compound And forming a molding on the surface, and 4) removing the molding from contact with the sprayed mold surface.

The present invention is further directed to an apparatus for mixing the components of the liquid spray mixture and spraying it onto a suitable surface.

That is, the invention includes an apparatus for depositing a mixture of supercritical fluid containing a release agent, which comprises: a) a closed vessel means for forming the supercritical fluid; b) a viscosity of the release agent. A means for lowering, c) a means for binding a release agent and a supercritical fluid and keeping the supercritical fluid in a supercritical fluid state, d) a means for spraying the above-mentioned bound material on a release surface in a supercritical state, and e ) A mold release surface as described above for depositing a mold release agent.

The present invention uses a supercritical fluid when spray-applying a release agent onto a surface, and applies a releasable material to the surface containing the release agent, which is subsequently released. A method of pulling the material away from contact with its surface.

First of all, it should be appreciated that in describing a supercritical fluid as a solvent for a release agent, this includes dissolving the release agent with the supercritical fluid. The present invention is not limited to the dissolution of the releasing agent with the supercritical fluid, and the present invention also includes dispersions and suspensions of the releasing agent with the supercritical fluid. Thus, when there is a tendency for overall solubility as the sole function of a supercritical fluid, this term of solubility means that the release agent is in a more dilute and flowable state by the supercritical fluid. Therefore, the release agent is dissolved, suspended or dispersed by the supercritical fluid so that the combined fluidity thereof has a lower viscosity and a more fluid composition for transporting the release agent. Means to be characterized by.

The phenomenon of supercritical fluid is well described, for example, "CR," published by CRC Press Inc. of Boca Raton, Florida.
C Handbook of Chemistry and Physics "67th Edition (1986-1
987), pages F-62 to F-64. Supercritical fluids or "dense gases" produced at high pressures above the critical point have densities approximating those of liquids and exhibit some of the properties of fluids. These properties depend on the composition, temperature and pressure of the fluid.

The compressibility of a supercritical fluid is very large just above the critical temperature, where a small change in pressure causes a large change in the density of the supercritical fluid. The "liquid-like" behavior of supercritical fluids at higher pressures results in higher diffusion constants and an extended effective temperature range compared to liquids, with a much higher solubilization capacity compared to subcritical compounds. give. Various high molecular weight compounds can be dissolved in supercritical fluids at relatively low temperatures. One of the interesting phenomena associated with supercritical fluids is the appearance of a threshold pressure for the solubility of high molecular weight solutes. As the pressure rises, the solubility of the solute often increases by many orders of magnitude with only a slight increase in pressure.

Near supercritical liquids also exhibit solubility characteristics and other relevant properties similar to that of supercritical fluids. The solute becomes liquid at supercritical temperature, even though it is solid at lower temperatures. In addition, fluid "modifiers" are often done at relatively low concentrations and can significantly alter the properties of supercritical fluids and, for some solutes, greatly increase solubility. Such modifications shall be included in the concept of supercritical fluid in the specification of the present invention. Therefore, the term "supercritical fluid" used in the present text refers to a state at or above the critical temperature pressure of a compound, or at a temperature slightly below the critical temperature pressure or the warp temperature.

Examples of compounds known to be usable as a supercritical fluid are shown in Table 1.

Carbon dioxide is preferably used when the present invention is realized because it is inexpensive, has low toxicity, and has a low critical temperature. For similar reasons, nitrous oxide (N ₂ O) is one of the preferred supercritical fluids in practicing the present invention. However, it should be appreciated that the use of any of the various supercritical fluids described above and mixtures thereof is within the scope of the present invention.

The solubility of supercritical carbon dioxide is similar to that of lower aliphatic hydrocarbons, so supercritical carbon dioxide can be considered as an alternative to the hydrocarbon solvent of conventional mold release agent compositions. In addition to the ecological benefits of replacing various hydrocarbon solvents with supercritical carbon dioxide, there are safety benefits as well because carbon dioxide is non-flammable and non-toxic.

The object of the present invention is to use such compounds in combination with a release agent for the application of the release agent to a release surface. The use of various compounds described above as supercritical fluids in the practice of the present invention determines whether the mold release agent is a waxy material, a liquid material, or whether an active solvent is present, etc. Depending on various considerations such as.

Various release agents exist in many forms and composition forms.
Most mold release agents are waxes, wax-like or grease-like. For example, hydrogenated vegetable oils such as shortening oil, lecithin and other food release agents are solid waxy or grease-like substances at the actual food manufacturing temperature. In addition, there are various liquids that can be used as release agents. Given the various functions of the release agent, it is desirable that the release agent be a material that has minimal flow properties on the release surface. It is desirable that the release agent does not exhibit fluidity on the release surface such that the release agent prevents uniform application of the material to be separated from the release surface. Therefore, upon application, the release agent should remain substantially fixed to the deposited surface of the release agent without any substantial migration from its point of application.

An important advantage of the present invention is that it provides a thin, uniform layer of release agent on the release surface. This layer is usually much thinner than that produced by the normal spraying of release agent onto the release surface. The layer of release agent on the release surface can be, but need not be, a continuous coating on the release surface. However, there is a greater possibility that a continuous film will form when the release surface is heated. If the release agent has a flow if it deposits on the release surface, the sprayed particles on the release surface tend to coalesce. Such aggregation typically results in fusion of the particles, thereby forming a continuous coating of fused particles as described above. Even with such coalescence, it is not necessary for the particles to lose their essence of a fine state during coalescence. That is, a continuous coating of the above particles can be formed that maintains the essence of the particles by imparting a particle shape to the coating. In such cases, the topography of the coating is
It is irregular, reflecting the uniqueness of each particle. However, if the sprayed release agent particles do not aggregate on the release surface, the layer of release agent can be a thin mass of discrete particles on the release surface. The present invention accommodates the use of a layer of discrete particles of release agent in which a substantial portion of the particles are in a disassembled, intermittent mode. In such a case, even though a part of the release surface is clearly exposed to the material deposited on the release agent, the small size of the release agent particles and the density of the layer of particles on the release surface will The surface is protected from contact with the material. It is this combination of particle size and layer density that ensures good strippability. The particle size of the release agent deposited on the release surface is not strictly critical. These particles can be liquid or solid. If the particles were very small, it may indicate that the release surface needs to be sprayed for a longer period of time to achieve the desired density of release agent coating on the release surface. Indicates that if the particles were very large, it would be desirable to perform a release agent flow over the release surface to produce an assembly that provides the desired coverage to achieve the desired level of release. There are cases. The release agent particles supplied for spraying the release surface are generally at least 1 micron (μ) in diameter, preferably about 2 to about 100μ, and most preferably about 5 to about 50μ. The release agent coating thickness can vary widely, so the release agent film thickness is not strictly critical in the practice of the invention. Most commonly, it is desired to apply a coating to the release surface that is at least 1 micron thick but no more than 100 micron. In special cases, the coating thickness is as high as 4 mils, and the usual thickness is significantly less.

Release agents used for molding purposes are waxes, wax analogs or greases, or derived from petroleum sources, or containing silicones (ie polydimethylsiloxane), or long chain saturated such as stearic acid. It is a liquid that constitutes a combination of two or more fatty acid salts. The choice of release agent is constrained to the composition to be molded or otherwise applied to the release surface.
Desirably, the release agent is not compatible with the material to which it is applied so that it is soluble in that material.

A wide range of chemicals offered as release agents are commercially available. They differ from the following compositions: ethylene bis-stearamide, water-soluble sulfated oil, dioctyl ester of sodium sulfosuccinate, non-polar solvents and petroleum, monoalkyl primary amines, linear aliphatic hydrocarbons, polyolefins, Hydrogenated castor oil, methyl hydroxystearate, ester mixtures, petroleum-based fatty acids, ester blends, blends of fatty acid derivatives and surface-active compounds, dimethyl silicone fluids, silicone miker glycol emulsions, once, twice and 3 Double-pressed and food-grade stearic acid, single- and double-pressed, distilled oleic acid, phosphated monoglycerides and diglycerides, modified fatty acid amides, emulsions of dimethylsiloxane, amide wax, oleyl palmitamide, steer reel Erucamide, calcium stearate, zinc stearate, potassium and sodium ricinoleate, microcrystalline wax, N- (2-
(Hydroxyethyl) 12-hydroxystearamide, polyvinylpolypyrrolidone, crystalline aliphatic saturated polyethylene having a molecular weight of 500, crystalline aliphatic saturated high density polyethylene having a molecular weight of 700, crystalline aliphatic saturated high density polyethylene having a molecular weight of 1000, Crystalline aliphatic saturated high-density polyethylene having a molecular weight of 2000, emulsifiable high-density polyethylene, fatty amide-amine salt, fatty amide, synthetic wax, silicone oxyalkylene copolymer, methylphenyl silicone, lecithin and nonionic,
Surfactants such as anions, cations and amphoteric.

Suitable wax compounds for use in the present invention as a release wax are any waxes known to those skilled in the art of release formulations. Generally, a wax is a substance that is a plastic solid at ambient temperature, but becomes a low-viscosity liquid at an appropriately elevated temperature. These are insect waxes and animal waxes as well as petroleum waxes, polyethylene waxes, Fischer-Tropsch
Includes waxes, chemically modified hydrocarbon waxes and substituted amide waxes.

Silicone mold release agents typically comprise a silicone liquid composition such as polydimethylsiloxane or polymethylphenylsiloxane having a methyl or methyl and phenyl to silicon ratio of at least about 2, preferably about 2 or 2 or more. Use as a base. They can be compounded with solvents and hydrocarbon materials such as waxes.

Exemplarily, the release agent, such as the wax component of the release composition, is generally 0.1 to 30 based on the total weight of the release composition.
It is present in amounts ranging over the weight percent. Preferably the wax component is 0.5 to 20% by weight on the same basis.
Present in an amount ranging over.

As noted above, the mold release agent can be used in the practice of the present invention without the use of solvents other than supercritical fluid solvents. Active solvents other than supercritical fluids suitable for the practice of the present invention include any solvent or solvent mixture capable of dissolving, dispersing or suspending the release agent system in combination with the supercritical fluid. It is quite clear that the choice of solvent is related to the release agent used. Solvents are typically hydrocarbon-based materials because most mold release agents are lipophilic.

In general, the solvents suitable for the present invention should have the desired solvency properties as described above, as well as a suitable equilibrium of evaporation rates to ensure good coating formation of the release agent. A review of the structural relationships important in the selection of solvents or solvent mixtures is given by Dileep et al. In Industrial and Engineering Chemistr.
y Product Research and Development 24 162, 1985 and Francis, AW Journal of Physical Chemistry 5
8 , 1099, 1954.

In order to reduce or minimize unwanted volatilization of any active solvent present in the fluid spray mixture, the amount of active solvent used is such that the viscosity allows the application of the mixture by the fluid spray method. It should be less than that required to form a mixture of release agent and active solvent. In other words, the active solvent content should be reduced or minimized so that the dilution effect due to the presence of the supercritical fluid diluent is fully utilized.

Suitable active solvents include: hexane, heptane, octane, nonane, decane, undecane, dodecane, and other aliphatic hydrocarbons such as high molecular weight aliphatic hydrocarbons; benzene, toluene, either alone or in mixture,
Aromatic hydrocarbons such as xylene and other aromatics; halogenated methane, ethane, propane and higher molecular weight homologs and halogenated aliphatic and aromatic such as halogenated benzene and the like. Hydrocarbons; oxygenated solvents such as alcohols, ketones, aldehydes, ethers, esters, glycol ethers, glycol ether esters and others; water; surface actives such as nonionic, anionic, cationic and amphoteric surfactants Including agents.

Generally, the amount of active solvent (other than the supercritical fluid) should be minimized so that the beneficial effects due to the presence of the supercritical fluid are maximized. It is preferred that the only solvent used with the release agent is a supercritical fluid. However, using only the supercritical fluid, the desired solvency of the release agent,
No dispersibility or suspension can be achieved. In such cases, other active solvents are provided in the release agent formulation. Overall, the other solvent should be present in an amount ranging from 0 to about 70% by weight based on the total weight of the mold release agent, solvent, and in this case the supercritical fluid called diluent. In such cases, the solvent will more typically range from 0.15% to 60% by weight, most preferably 0.3% on the same basis, in the formulation of the release agent formulation, based on the weight of the total release composition. It is present between weight% and 30 weight%. Most preferably the solvent is present in an amount ranging from about 0.5 to 30% by weight on the same basis. In choosing a wax compound and an active solvent other than a supercritical fluid solvent, the fact that the spray temperature cannot exceed the temperature at which thermal degradation of any component in the liquid spray mixture occurs should be taken into account. Therefore, these components do not deteriorate under spraying conditions.

The supercritical fluid diluent should be present in an amount such that it forms a fluid mixture having a viscosity such that it can be applied as a fluid spray.

If a supercritical carbon dioxide fluid is used as the supercritical fluid diluent, i.e. another active solvent is present, preferably CO ₂ is sprayed in the mixture together with the release agent and other active solvent. It should be present in an amount ranging from about 10 to about 95% by weight, based on the total weight of the ingredients forming the possible release agent formulation. Most preferably CO ₂ is present in an amount ranging from about 20 to about 95% by weight on the same basis.

When the mold release agent is mixed with increasing amounts of supercritical fluid in the absence of another active solvent, the composition may to some extent separate into two separate phases. Addition of a supercritical fluid such as a supercritical carbon dioxide fluid prior to this condition facilitates the viscosity of the viscous mold release agent composition by allowing it to pass through the spray orifice of an airless spray gun. To the extent that it can be sprayed on. After spraying, most of the carbon dioxide evaporates, leaving essentially the composition of the original release agent formulation. The fluid mixture of the residual release agent and solvent component flows when contacting the substrate and is thin on the substrate,
It produces a uniform and smooth film. If the mold release agent is a wax and no separate active solvent is used, the mold release agent can solidify as finely deposited particles on the release surface.

It should be understood that in the practice of the present invention, it is not necessary to specifically add the components of the release composition continuously. However, it is often preferred to first mix the mold release agent, such as a wax mold release agent, with the active solvent other than the supercritical fluid, if used.

The method and apparatus of the present invention comprises means for producing a pressurized mixture containing a release agent and a supercritical fluid, the pressurized mixture on a release surface (on which the release agent is deposited). Spraying means, means for introducing the material to be released from the release surface, and releasing the material from contact with the release agent and the release surface.

In this situation, the pressurized mixture of release agent dissolved, suspended or dispersed in the supercritical fluid is transported to the nozzle of the spraying device, where the fluid containing the release agent passes through a relatively narrow orifice. Ejects rapidly into an enlarged area that creates an immediate pressure drop therethrough. This rapid pressure release tends to cause the supercritical fluid to immediately expand into a gas or vapor at a much greater expansion rate than the higher density mold release agent and any active solvent entrained with the mold release agent. is there. The release agent and any entrained solvent are crushed into discontinuous particles, and the gaseous or vaporous component that was the supercritical fluid disappears from the particles into the atmosphere.

The spray pressure used in the practice of the present invention is a function of the release agent formulation, the supercritical fluid used, and the viscosity of the liquid mixture. The minimum spray pressure is the critical pressure of the supercritical fluid, or a pressure slightly lower than that. Generally the pressure is less than about 5000 psi. Preferably, the spray pressure is above the critical pressure of the supercritical fluid and below about 3000 psi. If the supercritical fluid is a supercritical carbon dioxide fluid, the preferred spray pressure is between about 1070 psi and about 3000 psi. Most preferred spray pressures are about 1200 psi and about 2500 p
between si.

The spray temperature used in the practice of the present invention is a function of the mold release agent formulation, the supercritical fluid used, and the concentration of the supercritical fluid in the liquid mixture. The minimum spray temperature is the critical temperature of the supercritical fluid, or a temperature slightly lower than that.
The maximum temperature is the maximum temperature at which the components of the liquid mixture do not thermally degrade significantly during the time the liquid mixture is at that temperature.

If the supercritical fluid is a supercritical carbon dioxide fluid, the supercritical fluid escaping from the spray nozzle condenses solid carbon dioxide and any ambient water vapor present due to the high humidity in the environment surrounding the spray. The spraying composition is preferably heated prior to spraying, as it may cool to the point of application. The minimum spray temperature is about 31 ° C.
The maximum temperature is determined by the thermal stability of the ingredients in the liquid mixture. The preferred spray temperature is between 35 ° C and 90 ° C. The most preferred temperature is between 45 ° C and 75 ° C. Liquid mixtures with large amounts of supercritical carbon dioxide fluid generally require higher spray temperatures to prevent greater cooling effectiveness.

The spray typically cools rapidly as it approaches the orifice, causing the temperature to drop rapidly to near or below ambient temperature. If the spray cools below ambient temperature, the entrainment of ambient air in the spray causes it to warm to or near ambient temperature before it reaches the substrate. This rapid cooling is advantageous. Because, during spraying, a smaller amount of active solvent evaporates compared to the amount of solvent lost in a conventional heated airless spray. Therefore, a greater proportion of active solvent is retained in the release agent formulation to facilitate leveling of the release agent on the release surface substrate. Conventional heated airless sprays also cool to ambient temperature before reaching the release surface substrate due to evaporation of solvent and entrainment of ambient air.

Spray temperature maintains the spray temperature by heating the liquid mixture before it enters the spray gun, heating the spray gun itself, circulating the heated liquid mixture to or through the spray gun. thing,
Alternatively, it can be obtained by a combination of these methods. It is preferred to circulate the heated liquid mixture through the spray gun to avoid heat loss and to maintain the desired spray temperature. Capillaries, tubing, hoses and spray guns are preferably insulated or heat traced to prevent heat loss.

The environment in which the liquid spray of the present invention is conducted is not strictly critical. However, the pressure in the environment must be below the pressure required to maintain the supercritical fluid component of the liquid spray mixture in the supercritical state. Preferably, the present invention is carried out in air at or near atmospheric pressure. Air with a small amount of oxygen content, or nitrogen, carbon dioxide, helium,
Other gas environments such as an inert gas such as argon, xenon or mixtures thereof can also be used. Oxygen or oxygen-rich air is undesirable. This is because oxygen enhances the combustibility of organic components in the spray.

The method of the present invention can be used to apply a release agent by the application of liquid spray to various release surface substrates. Therefore, the choice of substrate is not critical to the practice of the invention. Examples of suitable substrates are metal, wood, glass, plastic, paper, cloth, ceramic, brickwork,
Includes but is not limited to stone, cement, asphalt, rubber and composites. The substrate can be a conductor or a dielectric.

There is a wide variety of spray devices that can be used in practicing the present invention. Virtually any spray gun can be used, from conventional airless and air-assisted airless sprayers to electrostatic sprayers. The choice of spraying device is related to the type of coating in which the invention is used.

Airless sprays use a high pressure drop across the orifice to propel the release agent formulation at high velocity through the orifice. Upon exiting the orifice, the high velocity liquid breaks into droplets and disperses in air to form a liquid spray. Sufficient momentum remains after spraying to carry the droplets to the substrate. The tip of the spray is contoured to modify the shape of the liquid spray. This shape is usually round, elliptical conical or flat fan-shaped. A turbulence promoter may be inserted in the spray nozzle to facilitate atomization. Spray pressures typically range from 700 to 5000 psi. The required pressure increases with the viscosity of the fluid.

Air-assisted airless sprays combine the features of air sprays with the features of airless sprays. The air-assisted airless spray uses both compressed air and a high pressure drop across the orifice, typically a release agent formulation under milder conditions than each type of spray produces by itself. And forms a liquid spray. Compressed air pressure and air flow are generally lower than for air spray. Liquid pressure drops are generally lower than airless sprays but higher than air sprays.
Liquid spray pressures typically range from 200 psi to 800 psi. The required pressure increases with the viscosity of the fluid.

The present invention may use a compressed gas to assist in the formation of the liquid spray and / or to modify the shape of the liquid spray coming from the orifice. The auxiliary gas is typically at a pressure of 5 to 80 psi, preferably 5 to 20 psi
Low pressure compressed air, but with reduced oxygen content air or compressed nitrogen, carbon dioxide, helium,
It may be an inert gas such as argon or xenon or mixtures thereof. Compressed oxygen or oxygen-enriched air is undesirable. This is because oxygen enhances the combustibility of organic components in the spray. Auxiliary gases are directed into the liquid spray as one or more high velocity gas jets and are preferably symmetrically arranged on each side of the liquid spray to equilibrate one another. The auxiliary gas jet preferably comes from a gas orifice incorporated in the atomization tip and / or the nozzle. The auxiliary gas can also be ejected from an opening in the atomizing tip or nozzle that is a concentric ring around and around the fluid orifice to create a converging hollow cone high velocity gas jet over the liquid spray. However, this causes an undesirably large flow of auxiliary gas. The concentric annulus can be divided into multiple segments to reduce the gas flow rate and can be oval instead of circular to form a spray. Auxiliary gas flow rates and pressures are preferably lower than those used for air spray. The auxiliary gas can be heated to prevent the cooling effect of the supercritical fluid in the liquid spray.

Airless sprays and air-assisted airless sprays can also be used with heated liquid mold release agent formulations, or heated air, or both heated. Heating reduces the viscosity of the liquid release agent formulation and promotes atomization.

The fluid mixture of the mold release agent and the supercritical fluid is sprayed onto the substrate to form a fluid spray by passing the fluid mixture under pressure through an orifice and around the substrate to form a coating on the substrate. Form. An orifice is a hole or opening in a wall or housing, such as the spray tip of a spray nozzle on an airless spray gun, through which a fluid mixture of a release agent and a supercritical fluid with or without an active solvent. Flow from a high pressure area, such as inside the spray gun, into a low pressure area, such as the air environment around the substrate, outside the spray gun. The orifice may be a hole or opening in the wall of a high pressure vessel such as a tank or cylinder, and the orifice may be the open end of a tube or pipe or conduit through which the mixture exits. The open ends of tubes, tubing or conduits can be squeezed or partially blocked to reduce the open area.

Spray orifices, spray tips, spray nozzles and spray guns used for conventional electrostatic, airless and air-assisted airless spraying of coating formulations such as paints, lacquers, enamel and varnish are used as release agents with supercritical fluids. It is suitable for spraying the formulation, ie for spraying the supercritical fluid-containing mixture according to the invention. The spray gun, nozzle, and tip preferably do not have excessive flow volume between the orifice and the valve that intermittently redirects the spray. The spray gun can be automatic or manual spray. The spray gun, spray nozzle and spray tip must be constructed to withstand the spray pressure used.

The material of construction of the orifice has the necessary mechanical strength for the high spray pressure at which it is used, has sufficient resistance to abrasion to resist wear from the fluid stream, and is in contact with chemicals. It is not critical to the practice of the invention if it is inert to the drug. Any material used in the construction of airless spray tips is suitable, such as boron carbide, titanium carbide, ceramics, stainless steel or brass, with tungsten carbide being generally preferred.

A suitable orifice size for practicing the invention is about 0.004 diameter.
It ranges from inches to about 0.072 inches. Since the orifice is not generally circular, the diameter is equivalent to the circular diameter. The proper choice is dictated by the orifice size that provides the desired amount of release agent and yet achieves proper atomization to the release agent. Generally, small orifices are desirable at low viscosities and large orifices are desirable at high viscosities. A small orifice gives a fine mist but low power. Larger orifices give higher power but poorer spray. Therefore about diameter
Small orifices of 0.004 inches to about 0.025 inches are preferred. Most preferred is an orifice size of about 0.007 inches to about 0.015 inches in diameter.

The design of the spray tip, including the spray orifice, and the spray nozzle, including the spray tip, is not critical to the practice of the invention. The spray tip and spray nozzle should be substantially free of protrusions in the vicinity of the orifice that would or would hinder the spray.

Although the shape of the spray is not critical to the practice of the invention, it is important in some applications of the invention. The spray can be conical with a circular or oval cross section, or the spray can be a flat fan. However, the spray is not limited to these shapes. A flat fan or cone with an oval cross section is preferred for applications requiring extensive deposition of release agent. In such a case, a wide-angle fan shape is most preferable.

The distance from the orifice to the release surface is not critical to the practice of the invention. Substrates that generally undergo a broad release agent release are sprayed at a distance of from about 4 inches to about 24 inches. A distance of 6 inches to 18 inches is preferred, with an 8 inch to 14 inch distance being most preferred.

Devices and flow designs that promote a turbulent or agitated flow of the liquid mixture prior to passing the liquid mixture under pressure through the orifices can also be used in the practice of the invention. Such technologies include pre-ori-fice and diffuser.
er), turbulence plate, restrictor, flow splitter / combine
r), flow impinger, screens, baffles, vanes, and other inserts used for electrostatic, airless and air-assisted airless sprays,
Includes, but is not limited to, devices and flow networks.

Filtration of the liquid mixture prior to passing through the orifice is desirable in the practice of the invention to remove particulates that may clog the orifice. This can be done using conventional high pressure paint filters. A filter can be inserted into the spray gun to prevent clogging of the orifice and a tip screen can be inserted at the spray tip. The size of the channels in the filter should be smaller than the size of the orifices, and preferably significantly smaller.

Electrostatic forces are commonly used with orifice sprays such as air sprays, airless sprays, and air assisted airless sprays to increase the proportion of fluid release agent deposited from the fluid spray on a substrate. This is usually said to increase transfer efficiency. This is done by using a high voltage relative to the substrate to impart a negative charge to the spray. The substrate is rubbed electrically.
As a result, an electrical attractive force is created between the fluid spray particles and the release surface, which causes particles that otherwise could not reach the surface to deposit on the release surface. This effect is commonly referred to as wrap around when particles are deposited on the edge and backside of the substrate by the force of electricity. The release surface should be electrically conductive or be provided with a conductive surface before it is sprayed.

The fluid spray can be charged at any stage of the spray formation operation. A fluid spray is (1) in a spray gun by direct contact with a charging wall or internal electrode before passing through the orifice; By a discharge from an external electrode located; or (3) by passing a fluid spray away from the orifice and to or between the charging grid or the external electrode before the spray reaches the release surface, It can be charged by applying an electric current.

It is widely used to charge a fluid spray as it escapes from an orifice. Usually, short, pointed wires that extend away from the spray from the spray nozzle are used as electrodes. When a high voltage is applied to the electrode, a current flows from the tip of the electrode into the fluid spray, which becomes charged. This method is used for air spray, airless spray and air assisted airless spray guns. The method is used for both manual and automatic spray guns. Generally the voltage is 30 to 150
Cross the kilovolt range. A release agent formulation that is sufficiently conductive allows the charge to leak through the fluid and into the material delivery system. These material supply systems must be isolated (insulated) from the electrical ground so that they themselves become charged. For safety reasons, the voltage of a manual spray gun is usually limited to 70 kilovolts or less, and the device is designed to automatically shut off the voltage when the current exceeds safety standards. Generally for a hand spray gun, the useful current range is 20 microamps and 100
Between microamps and optimal results are obtained using a release agent formulation with very low electrical conductivity, ie very high electrical resistance.

This invention relates specifically to a fluid spray method,
In this method, a fluid spray mixture of a release agent and a supercritical fluid is charged by a high voltage compared to the substrate. Preferably, the substrate is grounded, but the opposite label may be charged as a fluid mixture or spray.
This substrate may be charged with a label on the same side as the fluid mixture or spray. But at a lower voltage with respect to ground, or this has little advantage. This is because, if the substrate is electrically grounded to the opposite sign, or if it is charged, a weaker electrical between spraying and substrate than if so. This is because it will generate an attractive force. Electrically grounding the substrate is the safest mode of operation. Preferably, the fluid mixture and / or the fluid spray are negatively (negatively) charged compared to the electric field.

The method of electrostatically charging the release agent-supercritical fluid mixture and / or spray is not critical to the practice of the invention, as long as the charging method is efficient. The fluid mixture is contacted with a high voltage relative to the substrate and current by (1) direct contact with a charged wall or internal electrode prior to passing through the orifice by a spray gun, As it emerges from the orifice, by discharging from an external electrode located near the orifice and adjacent to the spray, or (3) away from the orifice, before the spray deposits on the substrate, a charged grid ( It can be charged by application through a row of columns or external electrodes or by passing a fluid spray between them. The above methods (1) and (2) are preferably used individually or in combination. Method (2) is most preferred. In the charging method (1) above, the spray gun must be electrically isolated. A high voltage and current are supplied to the fluid mixture inside the gun by making direct contact with the electrically conductive and charged inner surface. This can be part of the wall of the flow condition inside the gun, or an internal electrode extending into the flow, or a combination of charging elements including a spray nozzle. The contact area must be large enough to carry sufficient charge to the fluid mixture as it flows through the gun. This internal charging method has the advantage of not having external electrodes that can interfere with the spray. The disadvantage is that, if the fluid mixture does not electrically insulate sufficiently, an electrical leakage can occur through the fluid mixture to the ground feed replenishment tank or feed discharge system. In this case, the amount of charge on the spray is reduced. If the leakage is too high, the feed replenishment tank and feed discharge system must be insulated from the electric field, ie charged to a high voltage. Leakage can be measured by measuring current flow from high voltage power supplies without fluid flow. The current that charges the spray is then the difference between the flowing current and the non-fluid current. The leakage should be small compared to the charging current.

In the above charging method (2), the fluid spray emerges from or near the orifice,
Charge the fluid spray. The spray gun and spray nozzle must be electrically isolated. The charge is provided by an external electrode near the spray tip and adjacent to the spray. Under high voltage, the current is discharged into the spray. Preferred electrodes are one or more metal wires placed adjacent to the spray. The electrodes may be in parallel, or perpendicular to the spray, or in any intermediate orientation such that the current from the socket (point point) is directed to the fluid spray. Good. The electrodes should be located close enough to the spray, preferably within 1 cm, to effectively charge the spray without being interfered by the flow of the spray. The electrodes can be sharply pointed and raised. In the case of a flat splat, it is preferred that one or more electrodes be placed on the side of the flat spray so that current is discharged to the surface of the spray. In the case of an oval spray, one or more electrodes are placed around the perimeter and close to the spray. The electrodes are arranged to effectively charge the spray. Modifying the electric field and current between the main electrode and the spray using one or more auxiliary electrodes that are at a different voltage than the main electrode or that may be electrically grounded be able to. For example, the main charging electrode is on one side of the spray fan and the ground insulated auxiliary electrode is on the other side of the spray fan. The charging method (2) has the advantage over the charging method (1) of less current leakage through the fluid mixture. A fluid mixture that is sufficiently conductive must have a feed replenishment path and a feed flow path insulated from the electric field.

In the charging method (3) above, the fluid spray is electrically charged far away from the orifice and disperses much better than in method (2). Therefore, a large circuit steel of the outer electrode is needed to effectively charge the spray. Therefore, this method is less secure and less flexible. Also, the distance between the electrode and the splat must be large to avoid interfering with the spray. Therefore, the charge delivered to the spray should probably be low. However, leakage through the feed channel is eliminated. The fluid spray is passed through or between a charged grid or array of external electrodes prior to the spray depositing on the substrate. The spray particles are charged by ion bombardment from a current discharged from the electrodes into the air.

The present invention can use high voltages in the range of about 30 to about 150 kilovolts. Although high voltage is convenient to impart a high charge to the fluid spray and make the substrate attractive, the voltage level must be safe for the charging and spray gun type used. For safety reasons, the voltage of manual spray guns is typically limited to 70 kilovolts or less, and the device is designed to automatically interrupt the voltage if the current exceeds a safe level. There is. Generally, for manual spray guns,
A useful range of currents is between 20 and 200 microampere, optimal results are obtained with coating formulations having very low electrical conductivity, ie very high electrical resistance. For remotely used automatic spray guns, higher voltages and currents can be used more safely than for manual spray guns. Therefore, the voltage can be used above 70 kilovolts up to 150 kilovolts,
The current can also exceed 200 microamps.

These methods of electrostatic charging are known to those skilled in the art of conventional electrostatic spraying.

It was surprisingly found that the supercritical carbon dioxide fluid is an insulating solvent with good electrical properties for electrostatic spraying. This fluid spray provides a good electrostatic wrap around the substrate. This demonstrates that the particles are highly charged and sustain an electrical charge.

Wet air may dissipate the electrostatic spray charge more quickly than dry air, and thus electrostatic attraction to the substrate and wraparound is less effective. Supercritical carbon dioxide fluid diluents are advantageous for spraying in humid environments. This is because carbon dioxide tends to replace the moist air around the spray as it leaves the spray. This helps the spray retain its charge for a longer period of time. If compressed air is used to assist electrostatic spraying, dry air is preferred over wet air.

For electrostatic spraying, the substrate is preferably a conductor such as metal. However, substrates that are not conductors or semiconductors can also be sprayed. The substrate is preferably pretreated to produce an electrically conductive surface. For example, the substrate can be dipped into a particular solution to impart conductivity to its surface.

The method of producing high voltage and current is not critical to the practice of the invention. High voltage power supplies can be used as in conventional electrostatic spraying. The power supply has a standard saf feature to prevent current or voltage surges.
should have an ety feature). The power supply can be incorporated into the spray gun. Other charging methods can also be used.

More information on orifice sprays, such as air sprays, airless sprays and air assisted airless sprays, heated orifice sprays and electrostatic sprays, can be found in the general literature of the coating industry, including: It can be obtained from the periodical publications issued by the manufacturer.

a.Marten, CR edition. Technology of Paints Vainishes an
d Lacquers. Chapter 36. Advanced edition.

Robert E. Krieg, Huntington, NY, USA
Published by er Publishing Compony.

b. By Fair, James. 1983. Sprays. Grayson.M. Kirk-
Othmer Encyclopedia of Chemical Technology. Third
Edition, Volume 21.

Wiley-Interscience, New York, USA.

By c.Zinc, SC. Carting Process. Grayson, M. Kirk-
Othmer Encyclopedia of Chemical Technology. Third
Edition, Volume 6.

Wiley-Interscience. D. Long, GE, New York, USA. 1978 (March 13th) Spraying Theorey and Practice Chemical Engineering
73-77.

e.Technical Bulletin. Air Spray Manual. TD10-2R.
Binks Manufact, Franklin Park, Illinois, USA
Published by uring Company.

f.Technical Bulletin. Compressed Air Spray Gun Pri
nciples. TD10-1R-4. Franklin Park, Illinois, USA. Published by Binks Manufacturing Company.

g.Technical Bulletin. Airless Spray Manual. TD11-2
R. Franklin Park, Illinois, USA. Binks Man
Published by ufacturing Company.

h.Technical Bulletin. Airless Spraying. TD11-1R-
2. Franklin Park, Illinois, USA. Binks Man
Published by ufacturing Company.

i.Technical Bulletin. Electrostatic Spraying. TD17
-1R, Franklin Park, Illinois, USA. Binks M
Published by anufacturing Company.

j.Technical Bulletin. Hot Spraying. TD42-IR-2. Franklin Park, Illinois, USA. Binks Manufact
Published by uring Company.

k.Technical Bulletin on air-assisted spray painting
system. Kremlin Inc, Addison, Illinois, USA
Issued orporated.

U.S. Pat.Nos. 3,556,411, 3,647,147, 3,754,
Nos. 710, 4,097,007 and 4,346,849 disclose spray nozzles and spray tips for use in airless sprays, including design, manufacturing methods and methods of promoting turbulence in spray fluids. There is. U.S. Pat.No. 3,659,
No. 987 discloses the use of spray nozzles and electrostatics for airless sprays. U.S. Pat.No. 3,907,202
And US Pat. No. 4,055,300 disclose the use of atomizing nozzles and static electricity for air assisted airless sprays. None of these patent specifications use supercritical fluids as diluents to spray the mold release agent formulations.

FIG. 1 shows a schematic view of a supercritical carbon dioxide batch device for spraying a release agent formulation. Eductor (ed
ucter) liquid carbon dioxide (bone-dry grade) cylinder (or any other CO ₂ source) 1 equipped with a pipe outlet 3, a valve 5 and a pressure gauge 7 supplies CO ₂ with valves 9, 17, 23 and 25 and tube 19,
It is supplied to the supply tank 31 via 21, 27 and 29. Valve 2
Close 8 and supply CO ₂ to tank 31. The feed tank 31 is weighed by a frame 33 to monitor the amount of CO _{2 in} the tank 31.
Supported above. An exit pipe 39 is provided in the tank 31, and the pressure in the tank 31 is controlled by a pressure gauge 41, a pressure relief valve 43 and a valve 37. When the CO ₂ pressure in tank 31 reaches the desired value, the supply from cylinder 1 is shut off by closing valve 25 or valve 17 or both. CO ₂ is supplied to the system via line 29 by opening valve 28, line 45, valve 47 and pump 49. Pump 49 is a Haskel ™ air driven piston pump (Haskel Incorporated Engineered Products Divi
sion, 100E Graham Place, Burbank, CA91502). The purpose of pump 49 is to maintain the desired feed rate into the container 59 through valves 53 and 57 and lines 51 and 55. The container 59 is a tank with a high pressure agitator and a jacket for mixing CO ₂ and a release agent. In this particular embodiment, the container 59 has a volume of 10 l. The container 59 is provided with a stirring means 61, thermocouples 62 and 64, and a charging funnel 71 attached to a valve 69. At the bottom of the container 59 is an outlet line with a valve attached.
There is a heat-controlled spray connection line 67 which connects to the container 59 via 63 and valve 65. Line 67 can be electrically heated to maintain the required supercritical temperature for the supercritical carbon dioxide fluid. The container 59 is a discharge exhaust line
It has an exhaust line 77 connected to a valve 79 connected to 81.
The pressure in the container 59 is monitored by the pressure gauge 75 and controlled by the pressure relief valve 73.

The supercritical fluid-release agent mixture is fed to the spray gun 85 via a heating line 67 with a thermocouple 83 and a thermocouple (not shown) at the start of line 67. The choice of spray gun is not strictly critical. It is possible to use a wide variety of spray guns, ranging from those that draw fine lines to those that produce a broader spray for typical industrial applications within the scope of this invention. it can. Release agent spray 87 has release surface 89
It is directed to. Carbon dioxide separates from the spray as the mixture is released from the spray nozzle, and the released CO ₂ is then vented to either the CO ₂ capture system or the atmosphere.

FIG. 2 schematically illustrates a continuous method and apparatus for spraying a release agent formulation onto a release surface. A liquid carbon dioxide (absolute dry grade) cylinder 90 supplies CO ₂ to a pump 92 via a pipe 91. CO ₂ is typically supplied at about ambient temperature. In pump 92 the CO ₂ is brought to a supercritical pressure such as about 1200 psi. The pressurized CO ₂ is passed through the pipe 93 to the heat exchanger 94. The supercritical CO ₂ formed in the heat exchanger 94 is passed through the pipe 95 and the pressure relief valve 96 into the mixing chamber 97. The mixing chamber 97 contains an impingement manifold that uses a static mixer (not shown). In order to mix the release agent with the supercritical CO ₂ in the chamber 97, the release agent and the solvent, if used, should be added via the funnel 101 to the mixing tank 98 equipped with a stirrer 99. Manufactured by. If the mold release agent is wax, the mixing tank 98 is equipped with a heating jacket to make the mixture of wax and solvent into a fluid state. The fluid release agent mixture is heat traced conduit 103.
And is removed from tank 98 using pump 105.
Line 107 can be electrically heated to maintain the required viscosity of the wax solvent mixture. The fluid mixture is passed from pump 105 via heat traced line 107 to valve 109. Pipeline 111 for effective temperature control
Recirculation of the fluid mixture through. A portion of the fluid mixture is passed via line 113 to the mixing chamber 97 where it is dissolved, suspended or dispersed in the supercritical carbon dioxide fluid. The supercritical fluid mixture containing the release agent is conveyed from chamber 97 via line 115, through open valve 117 to line 119, and then into high pressure vessel 12.
Carried to 1. An exhaust pipe line 135 connected to the valve 139 is attached to the high-pressure container 121. The pressure in the container 121 is controlled by the relief valve 141.

Release agent - a supercritical mixture of solvent mixture and the supercritical CO ₂ is supplied to the storage container 121 having an agitator 125 and then supercritical fluid - via the heat pipe 129 a mixture of release agent mixture valve A spray gun 131 is fed through 127 and then 133 is sprayed onto the release surface.

In FIG. 3, there is shown a perspective view of a wiring board on which a fine pattern of a release agent formulation in which an electronic circuit is drawn is sprayed on a substrate. In particular, a conventional composite wiring board 100 has a geometric pattern 102 spread over the top surface of which a release agent formulation 108 is sprayed. The release agent formulation 108 is a delicately focused spray ejected from a technician's airless spray gun 106. The spray gun contains a supercritical fluid-release agent mixture, a pressurized system similar to that shown in FIGS.
Supplied via 108 and heating line 110. The spray gun can be robotically controlled or manually controlled to deposit the release agent formulation within pattern 102. The remaining portion 104 of the substrate surface is left for the masking coating. FIG. 4 shows dip coating of the release agent treated wiring board 100 of FIG. 3 into a container 120 containing a coating material 122. After dipping the wiring board 100 in the coating 122, the wiring board is subjected to a treatment of drying or curing the coating as necessary,
The coated wiring board 100 can then be wiped according to the procedure shown in FIG.

FIG. 5 is a perspective view of the wiping procedure for removing the coating on the peeled surface of the wiring board subjected to the treatment characterized in FIGS. 3 and 4 above. In FIG. 5, the wiring board 100 having the coating 134 on the upper surface is subjected to gentle wiping or friction by rotating the roller 132 on the surface of the wiring board 100. Roller 132, which rotates counterclockwise in FIG. 5, has soft bristles on its cylindrical surface that gently wipe off the portion of coating 134 that is placed on pattern 102 having the release agent formulation applied. As a result, the remaining coated portion on the surface of the wiring board is a section such as 132. This operation can be repeated by cleaning pattern 102 until it contains no release agent formulation and then printing the circuit of the pattern. This procedure can be quite effective by using a coating that does not accept the coating procedure used to make the printed wiring. This same technique can be used to control the coating of many different types of objects. For example, the technique can be used to dip coat a part that is to be eventually welded to another part. Application of a release agent to the site for welding, then dip coating of the part, and then wiping of the part to strip the coating on the release surface, results in an uncoated weld surface. In this way, the parts can be coated more extensively than was possible if the parts were first welded and then the welded parts were collectively dip coated.

FIG. 6 demonstrates the scope of the invention. As shown in FIG. 6, the mold release agent spray 144 uniformly coats the inside of the baking container 140 via the spray gun 142.
To coat the inside. This procedure is amenable to automated procedures such as robotically controlled spray guns, which are flushed with a release agent formulation. As a result, the release agent can be applied as part of the assembly sequence. The mold release agent formulation can be a vegetable shortening dissolved in a supercritical fluid. Supercritical carbon dioxide is a preferred supercritical fluid for this purpose because it is inert to the mold release agent at operating temperatures.

A preferred object of the present invention is to demonstrate the use of supercritical fluids, such as supercritical carbon dioxide, as solvents for polyurethane foams in mold release formulations. Prior to the present invention, there were two release agent formulations for polyurethane foams, one based on hydrocarbon solvents and the other based on water. The water-based composition was not as effective at releasing as the hydrocarbon solvent-based composition. Formulations based on hydrocarbon solvents typically contain a wax that dissolves or disperses in a hydrocarbon solvent, such as naphtha. An aspect of using these hydrocarbon-based compositions is to spray a liquid formulation onto a heated mold surface. Upon contact with the mold surface, the hydrocarbons evaporate away from behind the wax coating on the mold surface. The wax layer thus deposited peels off the urethane foam without impairing the integrity of the urethane foam and with suitable skin properties. The method of the present invention provides effective release of polyurethane foam with minimal use of hydrocarbons.
The following examples further illustrate the advantages of the present invention in performing polyurethane foam demolding. The examples are purely illustrative and do not limit the scope of the invention.

Example 1 This example illustrates the actual application of a supercritical release agent in a batch process. The spraying device shown in FIG. 1 was used for this purpose.

A mold release agent formulation was prepared from 3,178 g of the mold release compound and 3,904 g of carbon dioxide. The releasing compound has a melting point range of 88 ° to 100 ° C.
Microcrystalline paraffin wax with 273g and boiling range 150
It contained 2,905 g of a hydrocarbon solvent having a temperature of ° to 190 ° C.
The total weight of the release composition was 7,082 g, of which carbon dioxide was 55.1% by weight, hydrocarbon was 41.0% by weight and wax was 3.9% by weight.

This composition was produced as follows.

The 10 liter high pressure vessel 59 was flushed with carbon dioxide from the high pressure carbon dioxide cylinder 1. The 10 liter container was brought to ambient temperature and pressure, and the release agent compound was charged into the container through the charging funnel 71. Seal the container 59 from the atmosphere and remove the Haskell (Hask
el) Carbon dioxide was charged into the container via the CO ₂ supply tank 31 using the pump 49. The 10l container 59 was then removed from the pump. The pressure in vessel 59 is 850 psig and the temperature is 20
It was ℃. Then open the line 67 to the spray gun 85,
The pressure was reduced to 700 psig. Spray gun 85 is a Graco ™ airless spray gun with a fan width of 60 ° and a 13 mil orifice at the tip of the spray. The contents of the vessel were heated to 38 ° C and the contents of line 67 were maintained at a temperature between 37 ° C and 40 ° C. The pressure in container 59 is
It was 2,400 psig. The contents of container 59 are then heated to high temperature (93
C.) was sprayed onto the internal molding surface of the laboratory mold for 4 seconds.
The spray produced was very fine and atomized. Prior to spraying the release composition, the hot mold surface was wiped clean of any residual wax from previous use. A typical HR (high resilience) urethane molding foam formulation with low water content (about 3.3 parts by weight per 100 parts by weight of total polyol) was poured into the mold at a molding temperature of 65 ° C and then the mold was sealed. The lid was opened at the end of the conventional de-mold time for this formulation (3 minutes of this time). It has been found that the polyurethane foam is easily and cleanly released from the mold. The foam had a good and smooth surface characteristic of this formulation.

Example 2 The same spraying equipment, mold release composition, mold, and urethane foam formulation described in Example 1 above was used. The contents of container 59 had a pressure of 2,050 psig and a temperature of 34 ° C. before spraying. The flexible hose 67 leading to the spray gun was 40 ° C at the end of the container 59 and 45 ° C at the end of the spray gun 85. The contents of container 59 are then
It was sprayed on the molding surface at 93 ° C. for 4 seconds. Prior to applying the release composition, the hot mold surface was wiped to remove any residual wax. The foam formulation was poured into the mold at 65 ° C and the mold was sealed. When the foam was removed from the mold, it released easily and cleanly. The foam had a good and smooth surface characteristic of this formulation.

Example 3 The same spraying device, mold release composition, mold and urethane foam formulation as in Example 1 above was used. The contents of container 59 had a pressure of 950 psig and a temperature of 33 ° C. before spraying. Flexible hose 67 was 40 ° C at the end of container 59 and 29 ° C at the end of spray gun 85. The contents of the container were sprayed onto the molding surface cleaned for residual wax for 4 seconds. The molding surface had a temperature of 93 ° C. Spraying is more than in Examples 1 and 2 above.
It was coarser. The foam formulation was poured into a mold with a surface temperature of 63 ° C and then the mold was sealed. When the foam was removed from the mold, it released easily and cleanly. The foam had a good and smooth surface characteristic of this formulation.

Example 4 The same mold and urethane foam composition as in Example 1 were used. The mold was heated to 93 ° C and wiped for residual wax as above. No release composition was sprayed onto the molding surface. The foam formulation was poured into the mold at a temperature of 63 ° C and the mold was sealed. When the foam was removed from the mold, the foam adhered to the mold and broke apart.

Example 5 The same mold and urethane foam as in Example 1 were used. The mold was heated to 93 ° C and there was no residual wax. Only carbon dioxide was sprayed onto the molding surface. The foam formulation was poured into the mold at a temperature of 65 ° C and the mold was sealed. When the foam was removed from the mold, it adhered to the mold and teared apart.

Example 6 The same spraying equipment, mold and urethane foam formulation as in Example 1 above was used. A mold release formulation was prepared from 454 g of a high solid mold release compound and 3,632 g of carbon dioxide. The high solids release compound contained 77.2 g of the wax characterized in Example 1 above and 376.8 g of the hydrocarbon solvent characterized in Example 1 above. The total weight of this release composition is 4,086 g, of which carbon dioxide is 88.9 g.
% By weight, hydrocarbon solvent was 9.2% by weight and wax was 1.9% by weight.

The composition was prepared at ambient temperature as described in Example 1 above. The release composition is then pressure 1350 psig, temperature
The container 59 containing the composition was heated so that it was at 52 ° C. The contents were then sprayed for 4 seconds onto the hot (93 ° C.) mold surface wiped for any residual wax.
The urethane foam formulation described in Example 1 above was poured into a mold at a temperature of 65 ° C and the mold was sealed. When the foam was removed from the mold, it released easily and cleanly with a good and smooth surface characteristic of this formulation.

Example 7 The same spraying device and mold as in Example 1 were used. A release formulation was prepared from 227 g of the high solid release compound described in Example 6 above and 4,540 g of carbon dioxide. The total weight of the release composition was 4,767 g, of which 95.2% by weight was carbon dioxide, 4.0% by weight was the hydrocarbon solvent and 0.8% by weight was the wax.

A mold release composition was prepared at ambient temperature as described in Example 1 above. Then the temperature is 50 ° C and the pressure is 1,
Vessel 59 was heated to be 500 psig. Then container 59
The contents of 3 were sprayed on the surface of a hot mold (85 ° C.) wiped for any residual wax for 4 seconds.
The urethane foam formulation described in Example 1 above was poured into the mold at 65 ° C and then the mold was sealed. When the foam was removed from the mold, it released easily and cleanly, yet had a good and smooth surface characteristic of this formulation.

Example 8 The same spray apparatus and release formulation as described in Example 7 was used. Also, a conventional air gun (Speedaire), solid (microcrystalline paraffin wax having a melting point range of 88 ° to 100 ° C and a boiling point range of 150 ° to 190 ° C, containing no supercritical carbon dioxide.
Mixture with a hydrocarbon solvent having a temperature of 8.6) and a release composition containing 8.6% by weight.

The mold release compound composition was sprayed onto 12 different containers using a conventional air gun. The inside of each container was sprayed for 4 seconds. The average amount of solids deposited per container was 4.18 g, and the standard deviation was 1.72. This corresponds to an average of 44.4 g of hydrocarbons released during each spray.

Spray device and mold release formulation as described in Example 7 above (solid
0.8 wt%, 4.0 wt% hydrocarbons, 95.2 wt% carbon dioxide) were used to spray into 12 different vessels. It sprayed for 4 seconds in each container. The average amount of solids deposited per container was 0.45 g, and the standard deviation was 0.16. This corresponds to an average of 2.20 g of hydrocarbons released during each spray. This average amount is the average amount of hydrocarbons released during spraying using conventional air gun and release compound compositions.
Represents 0%. Therefore, an average 95.0% reduction in hydrocarbon emissions was achieved with the use of the release formulation used in Example 7 above.

Example 9 The same spraying equipment, mold release composition and mold as described in Example 7 above was used. The mold release composition had a temperature of 50 ° C. and a pressure of 1,350 psig when it was sprayed onto the hot (87 ° C.) mold surface. Intermediate water content (total polyol 100
A urethane foam formulation (about 5.5 parts by weight water per part by weight) was poured into the mold at a temperature of 65 ° C and the mold was sealed. When the foam was removed from the mold, it released easily and cleanly, yet had the good and smooth surface characteristic of this formulation.

Example 10 The same spraying equipment, release composition and mold as described in Example 9 above was used. The release composition, when sprayed onto the surface of a hot (87 ° C) mold, has a temperature of 46 ° C and a pressure of 1,275 p
It was sig. High water content (about 6.5 parts by weight of water per 100 parts by weight of total polyol) Polyurethane foam formulation at 60 ° C
Was poured into the mold and the mold was sealed. When the foam is removed from the mold, it releases easily and cleanly,
Moreover, it had a good and smooth surface characteristic of this formulation.

Example 11 The same spraying equipment, mold release composition, urethane foam formulation and mold as described in Example 7 above was used. The mold releasing composition was placed on a high temperature (85 ° C) molding surface at a temperature of 43 ° C and a pressure of 1,10
Sprayed at 0 psig. The urethane foam formulation was poured into the mold and the mold was sealed. When the foam was removed from the mold, it was released easily and cleanly, and the surface of the foam had a good and smooth surface characteristic of this formulation.

Example 12 The same spraying equipment, mold release composition, urethane foam formulation and mold as described in Example 7 above was used. The mold release composition was heated (87 ° C) on the molding surface at a temperature of 43 ° C and a pressure of 1,00
Sprayed at 0 psig. The foam formulation was poured into the mold and the mold was sealed. When the foam was removed from the mold it released easily and cleanly and the foam had a good and smooth surface characteristic of this formulation.

Example 13 The same spraying equipment, mold release composition, urethane foam formulation and mold as described in Example 7 above was used. The mold releasing composition was placed on a molding surface at high temperature (87 ° C) at a temperature of 41 ° C and a pressure of 80
Sprayed at 0 psig. The foam formulation was poured into the mold and then the mold was sealed. When the foam was removed from the mold, it released easily and cleanly, yet had the good and smooth surface characteristic of this formulation.

Example 14 The same spraying equipment, urethane foam formulation and mold as described in Example 1 above was used. The release formulation comprises 22.8 g of microcrystalline paraffin wax, 68.2 g of aliphatic hydrocarbon,
And 4,540 g of carbon dioxide. The wax and hydrocarbon were charged to container 59 as described in Example 1 above. The total weight of this release composition was 4,631 g, 0.5% by weight was wax, 1.5% by weight was hydrocarbon,
And 98.0% by weight was carbon dioxide.

The mold release composition was sprayed onto a hot (87 ° C.) mold cleaned for residual wax at a temperature of 51 ° C. and a pressure of 1,450 psig. Place the urethane foam composition in the mold at 65 ° C.
Injection at a temperature of and then the mold was sealed. When the foam was removed from the mold, it released easily and cleanly, yet had the good and smooth surface characteristic of this formulation.

Example 15 The same urethane foam formulation and mold as described in Example 14 above was used. No mold release composition was applied to the molds cleaned for residual wax. The urethane foam formulation was poured into the mold at a temperature of 65 ° C and then the mold was sealed. When the mold was opened, the foam did not release, it broke apart.

The main points of the present invention are summarized below.

1. (i) A release surface is obtained by spray coating the solid surface area with a release agent obtained from a release agent formulation containing a solution, suspension or dispersion of a release agent and a supercritical fluid. Forming ;; (ii) depositing a mass of material on the release surface; and (iii) separating the mass of material or a product derived from the mass of material from a release surface. Method.

2. (i) A spray of release agent and release agent particles that evaporate from the release agent through the orifice into the low pressure zone outside the orifice and deposit on a predetermined area of the solid surface. A release surface is produced by spraying and coating a release agent obtained from a solution, suspension or dispersion with the supercritical fluid that forms, and (ii) a mass of material is deposited on the release surface containing the release agent. And (iii) separating the mass of material or the product derived from the mass of material from the surface coated with a release agent.

3. The method according to point 2, wherein the release agent deposition on the predetermined region is a substantially uniform film covering the predetermined region.

4. The method according to point 1, wherein the mass of material includes one of plastic, resin, elastomer, food preparation and protective coating.

5. The method according to point 1, wherein the deposited material block is a curable material.

6. The method of point 1 in which the spray coating comprises the uniform deposition of a thin layer of release agent on a predetermined surface area.

7. The method according to point 6, wherein migration of the release agent from a predetermined area is avoided.

8. The method according to point 1, wherein migration of the release agent into the material to be applied thereafter is avoided.

9. The method according to point 1, wherein the material mass or the product derived from the material mass separated from the release surface is obtained substantially without surface defects derived from the interaction with the release agent. Method.

10. Deposition (ii) is done by coating the area,
The method of point 1 wherein the coating separation (iii) is performed by brushing the coated surface until the coating is removed.

11. Molding of a thermosetting resin and a thermoplastic resin for forming a molded article, which comprises a mold release agent and a release agent sprayed on the inner molding surface of a mold in which the thermosetting resin and the thermoplastic resin are molded. A mold release agent obtained from a solution, suspension or dispersion consisting of a supercritical fluid that evaporates from the mold agent is sprayed, and then a thermosetting resin or a thermoplastic resin is supplied to the mold to contact the internal molding surface, And the method of claim 1 including molding, wherein the molded article is shaped into the shape given by the mold and the molded article is then removed from the mold.

12. The method according to point 1, wherein the supercritical fluid is carbon dioxide.

13. The method according to point 2, wherein the supercritical fluid is carbon dioxide.

14. The method according to point 3, wherein the supercritical fluid is carbon dioxide.

15. The method according to point 4, wherein the supercritical fluid is carbon dioxide.

16. The method according to point 5, wherein the supercritical fluid is carbon dioxide.

17. The method according to point 6, wherein the supercritical fluid is carbon dioxide.

18. The method according to point 7, wherein the supercritical fluid is carbon dioxide.

19. The method according to point 8, wherein the supercritical fluid is carbon dioxide.

20. The method according to point 9, wherein the supercritical fluid is carbon dioxide.

21. The method according to point 10, wherein the supercritical fluid is carbon dioxide.

22. The method according to point 12, wherein the supercritical fluid is carbon dioxide.

23. Key point 1 that the formulation contains a small amount of active solvent for release agent 1
2 Method described.

24. Key to Formulation Containing Small Amount of Active Solvent for Release Agent 13
The method described.

25. Key to Formulation Containing Small Amount of Active Solvent for Release Agent 14
The method described.

26. Key to Formulation Containing Small Amount of Active Solvent for Release Agent 15
The method described.

27. Essentials of Formulations Containing Small Amounts of Release Solvent Active Solvent 16
The method described.

28. Essentials of Formulations Containing Small Amounts of Release Solvent Active Solvents 17
The method described.

29. Essentials of Formulations Containing Small Amounts of Release Solvent Active Solvent 18
The method described.

30. Essentials of Formulations Containing Small Amounts of Release Solvent Active Solvent 19
The method described.

31. Essentials of Formulations Containing Small Amounts of Release Solvent Active Solvent 20
The method described.

32. Essentials of Formulations Containing Small Amounts of Release Solvent Active Solvent 21
The method described.

33. Essentials of Formulations Containing Small Amounts of Release Solvent Active Solvent 22
The method described.

34.a. forming a fluid mixture in a closed system, wherein said fluid mixture comprises: i. At least one release agent capable of forming a thin layer or coating on the molding surface, ii. B. At least one supercritical fluid, and iii. Optionally, a small amount of active solvent (s) capable of dissolving, suspending or dispersing the release agent; b. Spraying on top to form a thin layer of mold release agent on the molding surface; c. Introducing the molding composition to the molding surface having a thin layer of mold release agent on the upper surface and molding the composition in the mold Forming a molded product; and d. Separating the molded product from the mold.

35. Molding is reaction injection molding (RIM), injection molding, compression molding, bulk molding, transfer molding, cast molding,
Spin cast molding, casting, vacuum molding, blow molding, calender molding, lamination, foam molding, and rotational molding 1
Method described in point 34 depending on the species.

36.a. Forming a fluid mixture in a closed system, wherein said fluid mixture is: i. At least one capable of forming a layer on the molding surface
A wax compound, ii. At least one supercritical fluid, and iii. Optionally, a small amount of active solvent (s) capable of dissolving, suspending or dispersing the wax compound; b. . Spraying the fluid mixture onto a molding surface to form a thin wax layer on the molding surface; c. Introducing the molding composition to the molding surface having a thin wax layer of a release agent on the upper surface, Molding to form a molded product; then d. Separating the molded product from the mold;

37.a. Forming a fluid mixture in a closed system, wherein said fluid mixture is: i. At least one capable of forming a layer on the molding surface
A wax compound, ii. At least one supercritical fluid, and iii. Optionally a small amount of active solvent (s) capable of dissolving, suspending or dispersing the wax compound; b. Spraying the fluid mixture onto the molding surface by electrostatic means to form a thin wax layer on the molding surface; c. Introducing the molding composition to the molding surface having a thin wax layer of the release agent on the top surface. Molding the composition to form a shaped product; and then d. Separating the shaped product from the mold.

38. The method according to point 36, wherein the molding composition comprises a polyurethane-forming composition.

39. The method of point 37, wherein the molding composition comprises a polyurethane-forming composition.

40. The method according to point 38, wherein the polyurethane is a polyurethane resin.

41. The method according to point 39, wherein the polyurethane is a polyurethane resin.

42. The point that polyurethane is polyurethane foam 40
The method described.

43. The main point that polyurethane is polyurethane foam 41
The method described.

44. A process for the preparation of a mold, which comprises polymerizing an active hydrogen compound and an isocyanate compound in a mold to form a shaped article conforming to the mold, wherein said polymerization is preceded by: a. In a closed system: i. at least one wax compound capable of forming a layer on the molding surface, ii. at least one supercritical fluid, and iii. optionally, the wax compound can be dissolved, suspended or dispersed. Forming a fluid mixture comprising a small amount of active solvent (s); and then b. Spraying the fluid mixture onto a molding surface to form a wax layer on the molding surface. The method for preparing.

45. The method according to point 44, wherein a polyurethane foam is formed on the molding surface having a wax layer.

46.a. closed container means for producing a supercritical fluid, b. Means for reducing the viscosity of the release agent, c. A combination of the release agent and the supercritical fluid, and the supercritical fluid A means for maintaining a critical fluid state, and d. A means for spraying the supercritical compound on the release surface, and e. A release surface for depositing a release agent on the upper surface. Apparatus for the deposition of a supercritical fluid mixture containing a mold agent.

47. The method according to point 2, wherein the spray composition is heated before spraying.

48. Essential point is a minimum spray temperature of about 31 ° C and a maximum temperature determined by the thermal stability of the components in the liquid mixture 47
The method described.

49. The method according to point 48, wherein the spraying temperature is between 35 ° C and 90 ° C.

50. The method according to point 49, wherein the spraying temperature is between 45 ° C and 75 ° C.

[Brief description of drawings]

FIG. 1 is a schematic view of a spraying device that can be used in the present invention. FIG. 2 is a schematic view of another spraying device that can be used in the present invention. FIG. 3 is a perspective view of a wiring board on which a fine pattern of a release agent formulation is sprayed, in which an electronic circuit is drawn on the substrate. FIG. 4 is a cross-sectional side view of a segment of a dipping operation using the method of the present invention. FIG. 5 is a perspective view of the wiping procedure for removing the coating on the peeled surface of the wiring board subjected to the treatment characterized in FIGS. 3 and 4 above. Fig. 6 shows a pan (ba) prior to the addition of food preparations.
FIG. 3 is a perspective view showing spraying of a release agent according to the present invention on a king pan).

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventors Edmond, Joseph, Dardarian, West Virginia, United States, 25314 Charleston, Roden Heights Road 1864 (72) Inventor Eugene, Lawrence, Jarrett United States, West Virginia , 25177 St Albans, River Bend Bluebird 115 (72) Inventor Kenneth, Andrew, Nielsen 25303 Charleston, Stratford Place 108 Charleston, United States, West Virginia

Claims (4)

[Claims] 1. A method comprising: (i) spray coating solid surface areas with a release agent obtained from a release agent formulation containing a solution, suspension or dispersion of a release agent and a supercritical fluid. Forming a release surface; (ii) depositing a mass of material on the release surface; and (iii) separating the mass of material or a product derived from the mass of material from the release surface. The method that consists of. 2. A step of forming a fluid mixture in a closed system, wherein said fluid mixture comprises: i. At least one release agent capable of forming a thin layer or coating on the molding surface. Ii. At least one supercritical fluid, and iii. Optionally, a small amount of active solvent (s) capable of dissolving, suspending or dispersing the release agent; b. The fluid mixture. To form a thin layer of release agent on the molding surface; c. Introducing the molding composition to the molding surface having a thin layer of release agent on the upper surface, Forming the shaped product to form a shaped product; and d. Separating the shaped product from the mold. 3. A process for the preparation of a mold, which comprises polymerizing an active hydrogen compound and an isocyanate compound in a mold to form a molded article conforming to the mold, wherein said polymerization is preceded by: a. In the system: i. At least one wax compound capable of forming a layer on the molding surface, ii. At least one supercritical fluid, and iii. Optionally dissolving, suspending or dispersing the wax compound Forming a fluid mixture containing a small amount of active solvent (s) capable of forming; and b. Spraying the fluid mixture onto a molding surface to form a wax layer on the molding surface. The above method of preparing a mold by the method. 4. A closed container means for producing a supercritical fluid, b. Means for reducing the viscosity of a release agent, c. A release agent and a supercritical fluid are combined, and the supercritical fluid Means for maintaining the fluid in a supercritical fluid state; and d. Means for spraying the coalesced product in the supercritical state onto the release surface; and e. A release surface for depositing a release agent on the upper surface. An apparatus for the deposition of a supercritical fluid mixture containing a mold release agent.